Laboratory solenoids with induction upto 15T at 4.2 K

Two niobium-tin solenoids made of Soviet maaterials are described. The solenoids are characterized by high current density ( of the order of 15-20 kA/cm2) which permitted to make the windings rather small-size (30 and 45 mm internal diameters, 142 and 252 mm external diameters with the number of turns equalling 5820 and 12866) and applicable for laboratory tests. The solenoid inductance is 0.76 and 10.1 H, induction is 1208 and 15.02 T. Comparison of the main parameters of the above solenoids with foreign analogues shows that windings made of Soviet materials are much smaller in size than most foreign windings and surpass the best foreign samples in the mean current density